I checked my MP today and this is the result:
MP part number is MP-1-270-10050059.
The bearing is a 6302RS; 42mm diameter, 15mm hole, 13mm width. Available from McMaster-Carr in the US. I ordered a pair today, will report on the results. At least on the end I looked at, the bearing is secured by a circlip and is not a press fit so can be removed very simply. Whether this is true on the other end, I don't know yet since I haven't removed the other cover.
Michael